Disposable lids for drinking cups are well known, and are generally used in such circumstances were beverages are vended, dispensed or sold for consumption elsewhere. Such circumstances, of course, include the general sale of hot and cold beverages in coffee shops, cafeterias or offices, and in public places such as amusement parks or sports stadia, etc. One particular kind of sale that is specifically contemplated by the present invention, however, is the sale of hot and cold beverages--usually hot, such as coffee--from vending machines, road side restaurants and coffee shops, and the like, to persons such as truck drivers and salesmen who may wish to purchase their beverage and to drink it later while, perhaps, carefully driving their vehicle, or for persons purchasing or obtaining a cup of hot tea or coffee in such public modes of conveyance as airplanes or trains.
In any event, it is a principal purpose of the present invention to provide a disposable lid for a drinking cup, which lid is intended to substantially preclude spillage or splashing of beverage from the cup, after a small portion of the lid has been removed and disposed of so as to permit access to the beverage for purposes of consumption thereof. In these circumstances, it is contemplated that the user may remove a portion of the lid easily and without difficulty, and thereafter place the opening thus created to his mouth so as to drink the beverage.
It is accepted, however, by the present invention that once the opening has been created in the lid, it is the usual intention of the person having possession of the beverage in the cup to consume the beverage without necessarily wanting to re-seal the cup. In other words, it is accepted that there is neither any desire nor purpose to re-seal a cup if a portion of the lid has been removed; and that if the user has an intention to re-seal the cup after consuming only a portion of the contents, he would remove the lid from the cup rather than removing only a portion of the lid.
The present invention takes advantage of the fact that the material from which most disposable lids are made has a relatively thin cross-section, and is frangible or tearable. Most disposable lids are made from polystyrene or co-polymers having at least 70% to 90% by weight of styrene monomer component, or other suitable material; and in any event they are conveniently manufactured by extruding sheet material and vacuum forming the lids, after which they are cut and removed from the formed sheet for packaging. Because the material may be relatively easily torn, it is therefore not difficult to remove a portion of the lid away from the remainder of the lid, providing that the general size and shape of that portion is predetermined. This is particularly because of the toughness or resistance to tearing that the material of the lid may exhibit at the rim thereof--especially when the rim extends only a short distance from the wall of a cup onto whose mouth it is snugly received--and so as otherwise to preclude splashing or spilling the leverage.
However, the shape and size of a portion to be removed from the lid may be quite closely predetermined, by forming or making a pair of cuts in the rim, and by precluding the extent to which a tear will be made, in accordance with the present invention. At the same time, this invention recognizes and takes advantage of the fact that, when a tear is being made in a cup lid, it tends generally to extend inwardly at least from the inner side of the circumferentially extending cavity which receives and accommodates the mouth of the cup, in a generally radially directed fashion; that is, a tear which is made in a cup lid formed of relatively thin polystyrene or other suitable material will tend to be towards the center of the lid.
Several prior art patents are of interest, and they include the following:
Serritella, U.S. Pat. No. 3,800,999 issued Apr. 2, 1974, is particularly concerned with a lid having penetrable score lines that extend from the center of the lid at right angles to each other to the edge of the lid inside the rim of the cup, where they are joined by a straight fold score line, and an arcuate penetrable score line inside the rim of the cup. The score lines may extend across the edge of the lid to provide an option of breaking off the entire portion, but in any and all events the portion comprises two sides which extend to the center of the lid and which are at right angles to each other. The portion thus created is too large and promotes spillage because it is not manageable.
Lombardi, U.S. Pat. No. 3,977,559 issued Aug. 31, 1976, is particularly concerned with a re-sealable lid which has a flip-open section that extends from the peripheral edge of the lid along parallel or inwardly sloping sides to a pivot, whereby the flip-open section may be raised and lowered at will, about the pivot line. There is no substantial seal, however, because the beverage within the cup may pass through the slits that form the sides of the flip-open section, especially if the cup is jostled.
Elfelt et al., U.S. Pat. No. 3,994,411 issued Nov. 13, 1976 teaches a drink cup lid having two circumferentially spaced lines of performations formed in it, which extend equidistantly radially inwardly to spaced terminal points which eventually define a fold or pivot line. Means are provided for tucking a tab on the outer portion of the rim into a slot formed in the far central portion of the lid.
Schram et al., U.S. Pat. No. 4,090,660 issued May 23, 1978 teaches yet another disposable drinking cup lid, which again is particularly concerned with providing a pivot or fold area, and specifically is directed to precluding any tearing or breaking off the tab that is thus formed.
Deparales et al., U.S. Pat. No. 4,202,459 issued May 13, 1980, is also particulary concerned with a lid which has a segment that is reinforced so as to permit it to be bent numerous times without breaking.
Sequin, U.S. Pat. No. 4,210,272 issued July 1, 1980, also is concerned with the provision of a reclosable tear strip which has a hinge but which is particularly configured so as to preclude removal of the tear strip.
Wedzik, U.S. Pat. No. 4,285,442 issued Aug. 25, 1981, provides a pair of radially extending scored lines that converge towards each other and towards the center of the drinking cup lid, and the provision is made for segments that are adjacent to the center of the cup and cut completely through the material of the lid so that the user may remove a pie-shape piece of the lid by tearing it along the scored lines. In any event, the portion of the lid that is intended to be removed extends to the center of the lid.
Bailey, U.S. Pat. No. 4,322,015 issued Mar. 30, 1982 provides a lid which, once again, is particularly intended to have a reclosable strip that is terminated at its inner end by a fold line. The fold line, in this case, is defined by tear stop means which may be impressions or slits formed in the lid, localized thickenings or mechanical reinforcements, or otherwise; and in any event, as stated, the patent stresses a hinge or fold line rather than a removable portion.
In contradistinction to all of the above prior art, the present invention provides a lid for a drinking cup, where the lid is formed of frangible and tearable material of relatively thin cross-section compared to the diameter thereof, where a generally circular cavity is formed around the periphery of the lid and has a cross-sectional dimension so as to fit snugly over the lip of a cup when it is received in the cavity, and where there is a generally planar central portion inwardly of the cavity and a skirt portion depending downwardly and outwardly from the cavity, particularly having at least one pair of cuts formed in the rim of the lid at which the skirt portion terminates, and having a second cut made in the central portion of the lid through the thickness thereof in a place that is radially inwardly from the cavity at a distance less than the radius of the lid, where the second cut has a length so as to extend at least between imaginary diameters drawn through the rim cuts. The rim cuts are spaced apart from each other a distance less than 25% of the circumference of the rim, and generally about 30 to 60 degrees apart.
From the above, it is seen that the disposable lid accordingly to the present invention is such that a portion of the lid which does not extend inwardly to the center of the lid may be removed, without the necessity of or intention of hinging or folding that portion because, as stated, it is understood that once the opening has been made in the lid there is no effective way of resealing the lid. This practical consideration is, as noted, in contradistinction to most of the prior art, but practically recognized that it is usually the intention of the user to consume the beverage once a portion of the lid has been removed.